This invention relates to spring fasteners, and more particularly to those fasteners characterized by a structure suitable to be engaged in a slot.
A number of fasteners have been used in the past for securing one object on another object, as for example, securing an article such as for example a plastic sheet on a metal or other rigid plastic sheet. However, the fasteners being used presently are particularly designed for only a limited number of matching objects to be secured on each other. For sealing purposes, a secondary resilient sheet, or a resilient body attached to the fastener may be used.
Examples of conventional fasteners are disclosed in U.S. Pat. No. 5,542,158 (Gronau et al.); U.S. Pat. No. 5,422,789 (Fisher et al.), U.S. Pat. No. 5,373,611 (Murata); U.S. Pat. No. 4,609,170 (Schnabl); U.S. Pat. No. 3,864,789 (Leitner); U.S. Pat. No. 3,673,643 (Kindell); U.S. Pat. No. 2,825,948 (Parkin); U.S. Pat. No. 2,607,971 (Bedford, Jr.); U.S. Pat. No. 2,329,688 (Bedford, Jr.); U.S. Pat. No. 2,322,656 (Murphy), among others.
My U.S. Pat. Nos. 5,887,319 and 5,987,714, issued on Mar. 30, 1999, and on Nov. 23, 1999, respectively, describe self adjusting spring fasteners, and they are both incorporated herein by reference. These fasteners may be used by themselves, or with a resilient or elastic body attached to the fastener.
Elastic bodies which are suitable for the purposes of the instant invention are disclosed in U.S. Pat. No. 5,725,343 (Smith), and in the provisional application of Kanubhai Manibhai Patel, Michael Walter Smith and Edward John Smith, titled xe2x80x9cHigh Performance Sealing Fastenerxe2x80x9d, filed on Dec. 10, 1999, and which provisional application is incorporated herein by reference.
As aforementioned, this invention relates to spring fasteners characterized by a structure suitable to be engaged in a slot. More particularly, the invention pertains a spring fastener comprising a first side structure and a second side structure opposite the first side structure, the first side structure comprising a first wavelike multiple engagement spring having a first integral number of pairs of recesses and respective peaks, the second side structure comprising a second wave-like multiple engagement spring having a second integral number of pairs of recesses and respective peaks, the first integral number being different than the second integral number.
It is critical that both the first and the second engagement springs have a free upper end and an attached lower end, especially for easy installation, as well as space economy in the operation of the fastener.
Preferably, the first side structure and the second side structure are integrally connected to form a U-shaped configuration having a bottom and a top end, the top end having a top end length and two opposite extremities.
More preferably, the first wave-like multiple engagement spring has only one pair of a first recess and a respective first peak, while the second wave-like multiple engagement spring has only two pairs of recesses and respective peaks corresponding to a lower second peak, a lower second recess, an upper second peak and an upper second recess.
For increasing the operational flexibility of the spring fastener of the present invention, it is critical that the first peak is at a longer distance away from the bottom of the U-shaped configuration than the lower second peak, and wherein the first recess is at a longer distance away from the bottom of the U-shaped configuration than the upper second peak. For the same reason it is further important that the first recess is at a shorter distance away from the bottom of the U-shaped configuration than the upper second recess, and wherein the first peak and the second lower recess are substantially equidistant from the bottom of said U-shaped configuration.
In a different embodiment of this invention, the spring fastener comprises a first side structure and a second side structure opposite the first side structure, the first side structure comprising a first spring having a bent, the second side structure comprising a second spring, the second spring being a wave-like multiple engagement spring having recesses and peaks.
In the case of this embodiment also, it is preferable that the first side structure and the second side structure are integrally connected to form a U-shaped configuration having a bottom and a top end, the top end having a top end length and two opposite extremities. It is further critical that the bent is at a longer distance away from the bottom of the U-shaped configuration than the lower second peak.
In order to avoid irreversible insertion of the fastener into a respective slot, it is critical that the first spring also comprises a protective recess above the bent.
This invention also encompasses fasteners which comprise rigid supports over the two extremities of the top end, which rigid supports are especially useful in the case that the spring fastener further comprises a molded elastic body disposed under the top end, extending under the two extremities of the top end, and having a body length. In the absence of the rigid supports, it is important that the body length is at least 1.75 times the top end length.
In the case that the rigid extremities are present, the molded elastic body should be disposed under both the top end and both extremities of the top end, since the purpose of the rigid supports is to hold the elastic body in place.
This invention also relates to a vehicle comprising any of the fasteners in any of the variations described above.